The subject of the present invention is an autonomous apparatus for injecting a patient by infusion of a liquid contained in an infusion bag, the device including means for expelling the liquid from the said bag and for injecting it into the patient.
An application will be described hereinbelow for human infusion. It will be understood that the device of the invention may also find an application in the veterinary field.
The problem posed consists of injecting a patient, in general but without limitation at the scene of a road accident or other casuality, with a liquid by infusion. In general, the liquid is a biological liquid making it possible to compensate for the various water losses of the patient (for example a state of shock).
Conventionally, the liquid is contained in an infusion bag suspended from a bracket, or held by hand at least temporarily by the personnel administering treatment, from which it flows simply by the effect of gravity.
Although this configuration is perfectly functional in a hospital environment, the same is not true during emergency assistance, especially outdoors, for example at the time of road or other accidents.
To this end, a certain number of autonomous infusion devices have already been proposed, directly joined to a limb of the patient (arm or leg) or suspended therefrom by some means (belt clip, etc.).
None of tile known devices is entirely satisfactory.
Thus, in document FR-2,561,923, a device of this type is proposed, in which the infusion liquid is expelled from a bag by a piston actuated by a spring.
This device has the drawback of resorting to non-standard infusion bags and of exerting on the bag a pressure (force) which is not constant and which does not permit an even flow rate of the infusion liquid.
Similarly, document FR-2,570,949 describes a device of the same type for a standard infusion bag, in which the liquid is expelled by compressed air pressure. The bag is arranged in a leaktight chamber. It has not yet been possible to use these devices suitably, because of problems of leaktightness and regulation of the flow rate of the gas pressure.
Such devices furthermore require a pressure reducer and are therefore relatively expensive.